Chronic insomnia is reported by 10% of the general population and clearly has morbidity associated with it. But, it is often left untreated medically and a large percentage of people with insomnia (40%) self- medicate using over-the-counter (OTC) medications and alcohol, with 67% of those using alcohol reporting it was effective. This research program seeks to understand the risks associated with the use of ethanol as a hypnotic. There now is information that initially ethanol at low doses (i.e., doses insomniacs in the general population report using) improves the sleep of persons with insomnia and further, insomniacs self administer (SA) low ethanol doses at bedtime (i.e., as a hypnotic) to a greater extent than non-insomniacs with similar social drinking histories. The working hypothesis of this proposal regarding the risks of hypnotic ethanol use in the insomniac is that, while sleep is initially improved with ethanol, it's beneficial effects diminish rapidly and with "hypnotic" use of ethanol the insomniac finds its "mood-altering" effects reinforcing, thus leading to increased nightly ethanol intake extending beyond the hypnotic context and occurring in the absence of hypnotic effects. In other words, what may initially be sleep-medicating behavior, then becomes "mood-altering" behavior that begins to demonstrate some of the characteristics of drug-seeking behavior (i.e., alcoholic drinking). This proposal outlines three experiments to be conducted over the five year grant period. The studies are designed to explore each of three drug-seeking characteristics: dose escalation, enhanced daytime ethanol SA, and nightly SA in the absence of hypnotic effects. In the three studies attempts will be made to determine whether sleep effects, mood effects, or both determine the reinforcing function of ethanol for the insomniac and how those effects may change over time with prior exposure.